Control of Moisture Content for Paper Manufacturing

这笔赠款提供资金，用于制定一项控制造纸过程中水分含量的过程控制战略。 控制策略将利用纸张在制造时的含水量的估计值作为反馈。 除热干燥过程外，真空脱水过程将用作控制执行器。 水分含量的估计值将基于替代测量值，替代测量值是比水分含量更容易测量但与水分含量相关的量的测量值。 为了开发这种控制策略，将首先开发管理真空脱水中的水去除过程的本构模型。 将确定合适的替代变量，并建立描述这些变量与含水量关系的模型。 这些模型将在静态和动态脱水环境中进行验证。根据开发的脱水模型和替代测量模型，将开发估算含水量的算法。 控制算法将被开发、分析、优化、模拟，最后，实验测试。如果成功的话，本研究的结果将导致造纸中水分含量控制质量的提高。 准确和均匀的含水量对于纸张无卷曲、无褶皱以及不会导致打印机和复印机堵塞至关重要。 此外，由于能源密集型的热干燥过程将得到更有效的利用，预计能源支出也将减少。 本研究中开发的本构模型将提高对真空脱水的基本理解，这反过来又将导致未来造纸机的改进设计。

This grant provides funding for the development of a process control strategy for the control of moisture content in paper manufacturing. The control strategy will utilize as feedback, estimates of the moisture content of the paper as it is being manufactured. The vacuum dewatering process, in addition to the thermal drying process, will be used as the control actuators. The estimates of the moisture content will be based on surrogate measurements which are measurement of quantities that are more easily measurable than moisture content, but are related to moisture content. To develop this control strategy, constitutive models that govern the water removal process in vacuum dewatering will first be developed. Suitable surrogate variables will be identified and models that describe how they relate to moisture content will be developed. These models will be validated in both static and dynamic dewatering environments. Based on the developed models for dewatering and for the surrogate measurements, algorithms for estimating moisture content will be developed. Control algorithms will then be developed, analyzed, optimized, simulated, and finally, experimentally tested.If successful, the results of this research will lead to improvement in the quality of moisture content control in paper manufacture. Accurate and uniform moisture content is critical for paper to be curl free, cockle free and not cause printer and copiers to jam. In addition, reduction in energy expenditure is also expected as the energy intensive thermal drying process will be more efficiently utilized. The constitutive models developed in this research will improve the fundamental understanding of vacuum dewatering, which in turn will lead to improved designs for future paper machines.